The primary objectives of the proposed research are to isolate, purify, and characterize the proteoglycans of normal lung. A secondary objective is to carry out a limited metabolic study on normal lung proteoglycans and, if feasible, on inflamed lung tissue. Although mucopolysaccharides have been isolated from lung, there are no reports of the isolation and purification of the lung proteoglycans. In order to meet these objectives, we must devise adequate extraction and separation methods for a mixture of proteoglycans. We will begin by trying appropriate methods ("dissociative" extractions, electrophoresis, precipitation, and gradient centrifugation) that have been successful with cartilage proteoglycans. However, more vigorous modifications of the extraction methods may be necessary. In view of the complexity of the anticipated mixture of proteoglycans, new methods and new modifications of methods will probably have to be devised and proven. At all stages of fractionation, attempts will be made to compare lung proteoglycans with proteoglycans from other tissues. The ultimate aim is to obtain data which will allow us to determine the functional role of the proteoglycans in lung connective tissue. Thus, studies of the interaction of the proteoglycans will be performed by electrophoretic, centrifugal and column methods.